Light olefins (defined herein as ethylene, propylene, butenes and mixtures thereof) serve as feeds for the production of numerous chemicals and polymers. Light olefins traditionally are produced by petroleum cracking. Due to the escalating cost of crude petroleum, efforts to develop light olefin production technologies based on alternative feedstocks have increased.
An important type of alternative feedstocks are oxygenates, such as alcohols, particularly methanol, dimethyl ether, dimethyl carbonate and ethanol. Alcohols may be produced by fermentation, or from synthesis gas derived from natural gas, petroleum liquids, carbonaceous materials, including coal, recycled plastics, municipal wastes, or any organic material. Because of the wide variety of sources, alcohols, alcohol derivatives, and other oxygenates have promise as an economical, non-petroleum source for olefin production.
Because olefins, particularly light olefins, are the most sought after products from oxygenate conversion and catalytic petroleum cracking processes, a continuing need exists for new catalysts, new ways of making known catalysts, and/or new processes to:
increase the yield of olefin products; PA1 increase the yield of light olefin products; PA1 reduce the yield of unwanted products such as heavy hydrocarbons having molecular weights heavier than butane or low-valued by-products like methane; PA1 reduce coke formation; PA1 increase catalyst performance--life, maintenance, activity, selectivity, stability; and PA1 regenerate spent catalyst more easily and/or more efficiently.